#include<iostream>
#include<unistd.h>
#include<cstdio>
#include<cstring>
#include<sys/types.h>
#include<sys/wait.h>

void ChildWrite(int wfd)
{
    char c=0;
    int cnt=0;
    while(true)
    {
        write(wfd,&c,1);
        printf("child:%d\n",cnt++);
    }
}

void FatherRead(int rfd)
{
    char buffer[1024];
    while(true)
    {
        sleep(100);
        buffer[0]=0;
        ssize_t n=read(rfd,buffer,sizeof(buffer)-1);
        if(n>0)
        {
            buffer[n]=0;;
            std::cout<<"child say:"<<buffer<<std::endl;
        }
        else if(n==0)
        {
            std::cout<<"n :"<<n<<std::endl;
            std::cout<<"child退出 我也退出";
            break;
        }
        else
        break;
    }
}

int main()
{
    int fds[2]={0};//0读端，1写端
    int n=pipe(fds);
    if (n < 0)
    {
        std::cerr << "pipe error" << std::endl;
        return 1;
    }
    std::cout<<"fds[0]:"<<fds[0]<<std::endl;
    std::cout<<"fds[1]:"<<fds[1]<<std::endl;

    pid_t id=fork();
    if(id==0)
    {
        close(fds[0]);
        ChildWrite(fds[1]);
        close(fds[1]);
        exit(0);
    }

    //father
    close(fds[1]);
    FatherRead(fds[0]);
    close(fds[0]);
    sleep(5);

    int status=0;
    int ret=waitpid(id,&status,0);
    if(ret>0)
    {
        printf("exit code:%d,exit signal:%d\n",(status>>8)&0xFF,status&0x7f);
        sleep(5);
    }
    return 0;
}